Aging and Alzheimer’s Both Target Brain’s Key Memory Center

(HealthNewsDigest.com) - PITTSBURGH, – While aging and Alzheimer’s disease for the most part shrink different areas of the brain, both cause volume reductions in one critical region: the hippocampus – the brain’s key memory and learning center. These findings by University of Pittsburgh School of Medicine researchers, published in the online issue of Neurology indicate why old age is a significant risk factor for developing dementia.

Researchers found that as healthy people and those with Alzheimer’s disease grew older, there was shrinkage in the hippocampus. But grey matter volume reduction was more pronounced among the Alzheimer’s disease group and due to more than the normal aging process.

“Brain shrinkage of the hippocampus occurs both in normal aging and in Alzheimer’s, but this shrinkage is more dramatic in Alzheimer’s and is not a part of normal aging,” said lead investigator Cyrus A. Raji, Ph.D., who is in the combined M.D./Ph.D. program at Pitt’s School of Medicine. “With older age, shrinkage was shown in our study to affect many parts of the brain including the frontal lobes that control attention and planning. However, hippocampus volume is most reduced with aging and this may create a special vulnerability of that region to Alzheimer’s disease.”

Using high resolution 3-D volumetric scans from more than 200 elderly subjects enrolled in the Cardiovascular Health Study-Cognition Study, the Pitt researchers studied the effects of both normal aging and Alzheimer’s disease on the brain. Researchers used advanced 2mapping methods to study what parts of the brain are affected by both normal aging and Alzheimer’s in 169 cognitively normal people who stayed normal five years after their scan and 33 people with a clinical diagnosis of Alzheimer’s. The researchers accounted for gender, race and education.

“This study is a first step. We now need to understand why the unique factors with older age are causing brain shrinkage,” added study co-author Oscar L. Lopez, M.D., professor of neurology at the University of Pittsburgh School of Medicine. “If we can identify those factors, we may be able to reduce the risk for Alzheimer’s disease in the future.”

Co-authors of the study include Lewis H. Kuller, M.D., Dr.P.H., distinguished professor, University of Pittsburgh Graduate School of Public Health, and James T. Becker, Ph.D., professor, Department of Psychiatry, University of Pittsburgh School of Medicine; and Owen Carmichael, Ph.D., assistant professor, Department of Neurology, University of California Davis.

Funding for this research is provided by the American Heart Association and the National Heart, Lung, and Blood Institute.

This study, “Age, Alzheimer Disease, and Brain Structure” will appear in the Dec. 1 print issue of Neurology. For a high-resolution color photo describing the affected areas of the hippocampus, click here.

For more information about the School of Medicine, see www.medschool.pitt.edu.